Electric-socket plug.



E. B. NILSSON.

ELECTRIC SOCKET PLUG. APPLIOATION FILED 111111.25, 1911.

1,103533 Patent-,d July 14, 1914.

I UNITED STATES PATENT oFFIcE.

EMIL'B. NILSSON, 0F CHICAGO, ILLINOIS, ASSIGNOB TO CHI-ILL-ELECTRIC COMPANY,

' 0F CHICAGO, ILLINOIS, A CORPORATIONCF ILLINOIS. i

ELECTRIC-SOCKET PLUG.

Specification of Letters Patent.

application mea August 25, 1911.

Patented .ruiy ia, 1914. serial No. 645,939. y

Be it known that I, EMIL B.,N1LssoN, a subject of the King of Sweden, residing at Chicago, in the county of Cook and State of Illinois, have 'invented a new and useful Improvement in Electric- Socket Plugs, of which the following is a specification.

My object is to provide a novel and simple construction of socket-plug whichl may be economically and easily manufactured and the parts of which may be readily assembled.

My invention is illustrated in the'accompanying drawing, in which- Figure 1 is a view in elevation of an electric socket into which a plug constructed in p accordance withl my invention is screwed,

portions of the const-ruction illustrated being shown in section. Fig. 2 -is a longitudinal section of the plug, t-he section being taken at theA line 2 on Fig. 6, and viewed in the directionof the arrow. Fig. 3 is a View in eleva'tion of the contact-equipped member of the plug. Fig. 4 is a bottom view of the member of Fig. 3. Fig.. 5 is a plan View of the bushing forming a part of the plugstructure; and Fig. 6, a plan view of the.

construction illustrated in Fig. 2.

A socket in connection with which I have chosen to illustrate my invention is represented at 7 and is provided, as is usual in constructions of this character, with a contact 8, in the form of a threaded shell, and a centralized cont-act 9 formed of a springmetal strip 10. My improved plug, shown in Fig. 1 screwed into t-he socket to operative position, comprises, generally stated,

'a bushing 11, a member 12 of insulating material carrying binding-posts for the terminal wires, and a metal, threaded shell 13 screwingupon the bushing 11 and operating to releasably hold the latter and the member 12 together. =The bushing 11,- which is externally threaded atone end, as represented at 14, to receive the electric wires 16 and 17. is chambered at one end as indicated at 18, and extending intothis chamber are a pair of abutments 19 each affording shoulders 20 .and 21. The member 12, which by preference is of circular form Iand in ractice would preferably be constructed o porcelain, is formed with an oblong depending sect-ion 22,l and above said section is provided with alperipheral flange 23 which is cut away at one portion as indicated at 24 for a purposel hereinafter explained. One of the contacts for connection with one of the wires 16 or 17 .is represented at 25, this contact being formed of a strip of metal which extends through a slot 26 in the member 12 and is bent over, as represented at 27, to form a section which, when the plug is screwed into the socket 7 bears against the contact- 10, the lower end of the strip 25 containing a screw 28 which extends into a. groove 29 in the member 12 and forms a binding-post for .the terminal to be connected therewith; the other of the elect-ric contacts provided on the member 12 for the other of t-he terminals being represented at 3() and comprising, in its preferred embodiment, a 'split-ring 31 which rests against the upper side of the flange 23 and carries a depending plate-section 32 whichextends through the opening provided by cutting away the flange 23, as described, and carries a screw 33 which extends into a slot 34 in the member 12 and forms a binding-post for the terminal to be connected therewith, the ring 31' being of comparatively springy metal and being normally of larger diameter than the flange 23.

The shell 13, which is adapted lto be screwed upon the threaded portion 14 of the bushing 11 is provided with an annular inturned flange 35, the central opening 36 formed therein being of less diameter than the diameter of the ring 31.

The parts of the plug are assembled in the following manner: The bushing 11 is threaded, at its opening 15, upon the wires respectively. The member 12 is then po sit-ioned on the bushing 11 to cause the depending-section 22 of the member 12 to eX- tend into the chamber 18, and the flange 23 to seat on the top of the bushing, in which position of the member 12 the flat sides of the section 22 oppose the shoulders 20, and a lug 12a on the member 12 opposes one of the shoulders 21. The shell 13 is then screwed down upon the bushing 11 to cause it, at its `flange 35, to forcibly bear against the top of the ring 31 and clamp the member 12 and bushing 11 firmly together.

' The bushing 11 is insulated from both the member 12y and the shell 13, preferably by being formed of insulating material and the shell 13, which is insulated from the contact 25, yserves to make electrical contact with the shell 8 when screwed into the socket 7. The iianged end of the shell 13 is slightly constricted, as represented, and operates, when the shell is screwed tightly upon ythe bushing 11, to cause the ring 3 1 to be contracted cire'umferentially, thereby insuring a close fit of the shell 13 against the ring 31 and producing a contact therewith of relatively large area. l

To prevent the shell 13 from unscrewing from the bushing 11 in the operation of removing the plug from the socket 7, I prefer tofprovide means for releasably locking the shell on the bushing, a description of the lmeans which I prefer to employ for this purpose being as follows: The'free end of the ring 31 is provided with an up-turned lug 37 which extends opposite a recess 38 in the member 12 and has its outer face beveled in opposite directions, as indicated at 39 and 40, and engages with teeth 41 pro- -vided about the inner periphery of the flange 31, when the shell 13- is screwed into place upon the bushing 11 for the purpose, and as hereinbefore, described. It will be understood that when the shell 13 is screwed in to place on the bushing, the lug 37, which operates as a dog, will lock the shell 13 in place and thus even if the shell is relatively tightly held in the shell 8 of the socket, thev shell 13 will not unscrew from the bushing 11 in the operation of unscrewing the plug from the socket. lVhen it is desired to dis'- connect the parts of the plug, as for instance to replace the wiring, the shell 13 may be readily unlocked by contracting the ring 31 at its lug 37 to withdraw the latter from engagement with the teeth 41 on the flange 31, whereupon the shell 13 may b e readily unscrewed from the bushing 11.

The wires 16 and 17 extend on opposite sides of the section 22 of the member 12 and in securing the bushing 11, member 12 and shell 13 Yin assembled position, as described,

`the wires 1G and 17 are clamped between the i' corner-edges of the section 22and the corner edges of the opening 15 at its inner end,`

whereby any pull exerted on these wires at their free ends will not impair their connections with the binding-posts of the plug. What I claim as new, and desire to secure by Letters Patent, is-

1. An elect-ric-plug comprising a bushing, a member of insulating material provided with contacts for connection with the terminals of an electric circuit, and a metal shell surrounding said member and in electrical connection with one of said contacts and secured to said bushing and operating to `hold saidbushing'and member in assembled condition. L

2. An electric-plug comprising a bushing, a member of insulating material provided with contacts for connection with the terminals of an electric circuit, and a metal.

shell,I inA electrical connection with one of said contacts, surrounding said member and minals of an electric circuit interlocking with said bushing, and a metal shell in electrical connection with one of said contacts, surrounding said member and provided with means for holding saidvmember and bushing in assembled condition.

5. An electric-plug comprising a bushing, a member of insulating material interlock'- ing with said bushing and provided, with vcontacts for connection with the terminals of an electric circuit, and a metal shell screwing upon said bushing and against one lof said contacts and provided with means for holding said member and bushing in assembled condition.

t. An electric-plug comprising a chainbered bushing, a member of insulating material fitting into the cliambered portion of said bushing and provided with contacts for connection with the terminals of an electric circuit, and a metal shell screwing upon said bushing and against'one of said contacts and provided with means for holding said member and bushing in assembled condition.

7. An electric-plug comprising a bushinfr` a ,member of insulating material fitting 'against the end of saidl bushing and provided with contacts for connection with the terminals of an electric circuit, ,and a metal shell screwing upon said bushing andv provided with a flange bearing against one of said contacts and operating to hold said bushing and member in asseinbledcondition.

8. An electric-plug comprisin a bushing, a member of insulating material provided with contacts' for connection with the terminals of an electric circuit, one of said contacts being of curved form, and a metal shell screwing upon said bushing and pro vided with an inturned flange at one end operating to bear against said curved contact and hold said bushing and member iii assembled condition.

9. An electric-plug comprising a bushing, a member of insulating material seating against saidubushing and provided with a seat at one end thereof and with contacts for connection with the terminals of an elec- 1 and a metal shell screwing upon said bush- 4 ber in assembled condition.-

ing and provided with meanswhich bear agan'lst said curved contact and hold sa1d bushing and member in assembled condition.`

10. An 'electric-plug' comprising a bushing, a member of lnsulating material seating agamst said bushing and provided with a seat at one end thereof andwith contactsv for connection with the vterminals of an electric circuit, one of said contacts being in the form of a ring and bearing against said seat, and a metal shell screwing upon said bushing and provided"'with means which bear against said ring-contact and holdsaid bushing and member in assembled condition.

11. An electric-plug comprising a bushing, a member of insulating material seat-I ing against said bushing and provided with a curved seat at one end thereof and with contacts'for connection with the terminals of an electric circuit, one of said contacts being of spring metal and of curved shape and bearing against said seat, and a metal shell screwing upon said bushing and provided with means which bear against the face of said curved'contact and against the side thereof operating to spring said curved contact and to hold said bushing and mem- 12. An electric-plug comprising a bushing, a member of insulating. material seat-- ing against said bushing and provided with a circular seat at one end thereof and with contacts for connection with the terminals of an electric circuit, one of said contacts being in the form of a contractible ring and bearing against said sea-t, and a metal` shell screwing upon said bushing andv provided with a ange which bears against the face of said ring-contact and against the side thereof operating to contract the ring and to hold said bushing and member in assembled condition.

13. An electric-plug comprising a chambered bushing, a member of insulating material provided with a, peripheral flange and seating thereat upon said bushing and pro-- vided with contacts for connection with the terminals of an electric circuit, one of said contacts bearing against the outer face of said flange, and a metal shell screwing'upon said bushing and provided with a flange bearing against said last referred to contactand operating to hold said bushing and member in assembled condition;

14. An electric-plug comprising a bushing, a member of insulating material provided with contacts for connection with the terminals of an electric circuit, a metal shell for holding said bushing and member in as-v sembled condition, and means for releasably leaking said shell in operative position.

15. An electric-plug comprising a bushing, a member of insulating material provided with contacts for connection with the terminals of an electric circuit, a metal shell screwing upon said bushing and provided with meansfor securing together said member and bushing, and means for releasably locking said shell in operative position.

1G. An electric-plug comprismg a bushing, a member of insulating material pro'- vided With contacts for connection with the terminals of an electric circuit and interlocking with said bushing, ,a shell screwing upon said bushing and provided vwith means forsecuring together said member and bushing, and means on said member .engaging with said shell for releasably locking the latter aga-inst removal from said bushing.

l17. An electric-plug comprising'a bushf y ing, a member of insulating material provided with contacts for connection lwith the terminals of an electric circuit and interlocking with said bushing, a vmetal f shell screwing upon said bushing and provided with teeth and with means for securing' together said-member andfbushing,` and a said teeth, for the purpose set forth.

18. Ani electric-plugzcomprising a bushing, a member ofinsulating material inter- 'lockingt-herewith and provided with contacts` for connect-ion with the terminals ,of

spring-dog on said member engaging with an electric circuit, one of said contacts car-'- in-the'form of asplit ring carrying on one end a spring-dog, and a metal shell screwing upon said bushing and provided with an inturned annular flange serrated -along 'l its inner periphery, and operating, when the shell is screwed-in place on the bushing to bear' against said Aring-contact and engage at its serrations with said dog and secure said member and bushing together.

20. An electric-plug comprlslng a chambered bushing, a member of insulating mai terial extendlng into the chamber inv said bushing, a shell screwingupon said bushing and provided with means for clamplng said bushing and member together, electric contacts on said member, and'wires leading through said bushing and 'connected wlth said contacts and gripped intermediate their ends between said member and bushing, for the purpose set forth. l

21. In an electric-plug, the. combination with a block of insulating material provided with a recessed curved shoulder and containing an opening, a contact-plate of curved form fitting against said shoulder with contacts for connection with the ter-l minals of an electric circuit, and a metal shell releasably secured to said bushing and engaging with one of said contacts and provided withmeans for holding said member and bushing together.

23. An electric-plug comprising a chambered bushing, a member of insulating material provided with contacts for connection with the terminals yor an electric circuit and fitting into the chamber portion of said bushing, and a metal shell releasably secured to said bushing and engaging with one of said contacts and provided with means for holding said member and bushing together.

24. An electric-plug comprising a cham- Vbered bushing of insulating material, a member of insulating material provided with contacts for connection with the terminals of an electric circuit and fitting into the 'chamberof said bushing and against thel inner end of the latter, a shell secured to said bushing and electrically connected with one of said contacts, and means for holding said bushing and member in assembled condition.

25. An attachment plug comprising in combination'a hollow insulating cap provided with exterior screw threads, an insulating base, and a screw shell directly cooperating with the threads on the cap to secure the cap and shell together and also the insulating base within the cap, and locking means to prevent accidental relative rotation between the parts of the plug.

An attachment plugl comprising in combination a hollow insulating cap provided with exterior'screw threads, an insulating base, and a screw shell directly cooperating with the threads on the cap to secure the cap and shell together andalso the insulating base within the "cap, and locking means between the insulating base and the' `.combination a relatively small insulating cap having an exterior screw threaded cylindrical portion hollowed out to form a relatively large interior chamber for a large knot in the wires, a detachable insulating base, a center contact and connecting means for the wires carried by the detachable insulating base;v and a screw. shell contact detachably' securing the base to the cap.

28. An attachment plug, comprising in combination an insulating cap, a screw shell provided with locking means, an insulating base, and locking means carried by the insulating base to coperate with those carried by the screw shell. 'i

29. An attachment plug, comprising in y combination an insulating cap provided with a hollow cylindrical portion having eXterior screwthreads and with locking means to coperate detachably with locking means on an insulating base, an insulating base proy vided with lockingmeans to coperate .with those carried by the cap, and with additional locking means to detachably engage with a screw shell contact, and a screw shell con-` tact having locking means to detachably engage with the locking means carried by the insulating basca 30. An electric plug comprising a recessed bushing, a threaded metal shell on said bushing, a member telescoping with said bushing and provided with a. projection opposing the inner end of said bushing, electrical connections on said member for electric wires, a Contact on said member in circuit with one of said connections, means'electr'ically connecting said shell with the other of said connections, and means on said shell for holding said contact-equipped member in place.

EMIL B. NILSSON. In presence of- H. C. EsBJoMsoN, FREDERICK 'DEIsElL 

